Antiplane response of a flat-bottomed semicircular canyon to cylindrical elastic waves

The purpose of this study is to theoretically probe how the joint effects of near-field source and surface topography impact the seismic wavefields. A simplified canyon model, which couples a semicircular model with a model for minor segments, is used to predict characteristic changes in ground motions due to line-source excitation. Based on a semi-analytical procedure using the region-matching technique, a Fourier–Bessel series solution is derived. Distinct coordinate systems are unified with the aid of Graf’s addition formula. Comparisons with boundary-element solutions verify the modelling framework proposed. Steady-state and transient simulations are both conducted.